Apparatus and method for forming concrete panels

ABSTRACT

The invention provides a form member for use in forming concrete panels comprising a pair of upright walls connected by a plurality of ribs. Each of the ribs includes an aperture for allowing a fastener through. The fastener passes through each of the ribs into a casting floor to fix the form member to the floor. A plurality of form members can be arranged to define enclosures, concrete is then poured into the enclosures to the level of the upright walls, smoothed and allowed to cure to form concrete panels. The form members of the present invention allow a number of panels to be formed at the same time, with some form members common to more than one concrete panel. The invention provides easy of use and savings in space, time and labour.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an apparatus and method for formingconcrete panels. In particular, the invention relates to forming tilt-upconcrete panels which are poured on a flat surface and subsequentlytilted up to form walls for buildings.

2. Background of the Invention

Tilt-up construction is a method of forming concrete buildings. Itprovides a low cost and high speed way to construct buildings which arelow maintenance and have good durability.

Typically, in a tilt-up concrete construction, panels are formed as nearto their final position in the building as possible. The most convenientcasting base is often the concrete floor of the building. Wood or steeledge forms are prepared and positioned on a casting base. The base issprayed with a release agent that prevents wet concrete sticking to thebase. Reinforcing steel and any desired door and window frames, electricconduits and outlet boxes are then positioned within the form. Concreteis then poured into the form on the horizontal base, the poured concreteis screed, allowed to cure and subsequently tilted into a verticalposition and moved into place.

Placing and fixing the forms for the panels, and subsequently removingthose forms presents a number of problems. Typically, each form is madefrom plywood and is fastened to the forming surface by nails orself-tapping screws. The forms are often damaged when the nails orscrews are removed so that they cannot be reused. The casting surface isoften damaged as well.

A chamfer is often desired on the edge of the concrete panels. This isachieved by placing a chamfer strip or fillet adjacent to the formmembers. However, these strips can often be displaced when the concreteis poured leading to irregular panels being formed.

The plywood forms are of a height that is equal to the thickness of thepanel to be cast. Practically, this means that the panels are limited inthickness to standard plywood widths.

The forms have to be sufficiently strong to withstand the considerablepressure exerted by the poured concrete. In order to support the formmembers, supporting brackets are placed outside of the form members.This means that each panel requires a separate form and takes upconsiderable space on the casting floor. It is possible to cast a numberof panels side by side with a single form section forming a common wallbetween two panels. However, with existing systems, in order to do this,both panels must be poured at the same time in order to balance thepressure exerted on the form by the poured concrete. It is not possibleto stick brackets on either side of the form in this scheme as theywould interfere with the shape of the concrete panels. However, existingforms cannot be anchored strongly enough to the casting floor towithstand the pressure from the concrete without external brackets.

U.S. Pat. No. 6,322,045 discloses a system for forming tilt-up concretepanels in which each form member is comprised of an extruded base memberinto which a plywood panel is inserted to form the wall of the formmember. FIG. 1 shows a side view of a form of the type disclosed in U.S.Pat. No. 6,322,045. The form 1 comprises an elongate support into whicha plywood board 2 is inserted. The support comprises a pair of uprightwalls 3, 4 and a base member 5 defining a U-shaped trough into which theplywood is inserted. The support also includes a pair of chamferedsurfaces 6, 7 on either side of the U-shaped trough. The support isformed from a rigid material such as extruded aluminium and is anchoredto a casting surface using a self-tapping screw 8 in the base of thetrough.

There are a number of problems with the system of U.S. Pat. No.6,322,045. Firstly, concrete can enter the gap between the plywood andthe extruded form member. This will make it almost impossible to removethe plywood from the form member without significant damage to theplywood, making it unusable again. The plywood used to make the forms isa considerable expense in the process and as far as possible it isdesirable to be able to reuse the plywood form members.

Secondly, in order to minimise the above problem, the plywood must fitinto the support as tightly as possible. Plywood that has been sittingin the form member whilst concrete is curing will absorb moisture andwill expand. Not only will this make it difficult to remove the plywoodfrom the support but makes it almost impossible to refit it into asupport member for subsequent reuse. Furthermore, if a chip of theplywood breaks off during reinsertion and jams into the bottom of theextrusion, then this will create a misalignment in the height of theform as compared with adjacent form walls. The height of all the formwalls must be the same in order to create concrete panels of uniformthickness during the screeding process.

Thirdly, if the plywood does get jammed in the support and cannot beremoved then it is impossible to remove the support from the floor asthe screw is covered by the plywood. The entire section then remainslocked to the floor until the panel is lifted out. Not only will theplywood be damaged on removal from the support, but the form member canalso then be damaged by the panel lifting equipment during the liftingof the panel.

Fourthly, difficulties can arise when trying to unscrew the form memberfrom the floor. The screws used to attach the form member to the floorare necessarily very small. This is because the form members arerestricted to the thickness of standard plywood making the trough inwhich the screw sits quite narrow. If the screw head gets rounded theonly way to remove the form member is to stick a bar underneath thescrew head and prise it out. This damages both the form member and theunderlying concrete surface.

Fifthly, as with previous systems, if using a form wall as a common wallfor two panels, it is necessary to pour both panels simultaneously inorder to balance the pressure exerted by the concrete on the formmember. The top of the plywood will typically bend over and out ofalignment if concrete is poured on one side, creating an irregularshaped panel. Further damage can be caused to the plywood during pouringif the pump hose is dragged across the top surface or by the screedingmachine during screeding, preventing reuse.

Accordingly, it is an objection of this invention to provide a solutionto the abovementioned problems or to at least provide the public with auseful choice.

SUMMARY OF THE INVENTION

In a first aspect, this invention provides an apparatus for use informing a concrete panel comprising a rigid form member, the form membercomprising:

a pair of upright walls, having internal surfaces facing one another andexternal surfaces facing away from one another; and

a plurality of ribs connecting the internal surfaces of the walls,wherein the ribs each include an aperture to allow a fastener shafttherethrough.

Preferably, the form member further includes a base portion including atleast one chamfered surface extending outwardly from the exteriorsurface of one of the walls. More preferably, the base portion includestwo chamfered surfaces, one extending outwardly from each of theexterior surfaces of the walls. Preferably, each chamfered surface issubstantially non-perpendicular to the ribs.

Preferably, the apparatus further includes a bolt having a shaft and ahead, wherein, in use, the bolt shaft passes through the apertures andinto a floor. Preferably, the rib furthest from the floor provides aseat on which the bolt head rests. Preferably, in use, the upright wallsextend above the extent of the bolt head.

Preferably, the apparatus further includes a cap, adapted to cover thebolt head. Preferably, in use, the cap does not extend above the uprightwalls

The apparatus may further include an extension piece, adapted to fit onthe rigid form member at the opposite end to the base portion, theextension member comprising a pair of walls connected by a plurality ofrib members, the extension member adapted to provide additional heightto the rigid form member. Preferably, the ribs of the extension pieceeach include an aperture to allow a fastener therethrough.

Preferably, the form member is formed from an aluminium alloy.Alternatively, the form member may be made of any other rigid material.Preferably, the extension piece is formed from an aluminium alloy.Alternatively, the extension piece may be made of any other rigidmaterial.

Preferably the end of the form member is sealed between the uprightwalls.

According to a second aspect of the invention, a kit for formingconcrete panels comprises a plurality of form members in accordance withthe first aspect of the invention and a plurality of exterior formmembers, wherein each exterior form member comprises a first wall, and asecond wall, wherein the second wall is substantially perpendicular tothe first wall and connected to the first wall to form a corner, whereinthe second wall is substantially shorter than the first wall and whereineach of the first and second walls include apertures therethrough.

Preferably, the exterior form members are formed from aluminium alloy.Preferably, the exterior form members are formed in two parts.

According to a third aspect of the invention, there is provided a methodof forming a concrete panel, comprising the steps of:

arranging a plurality of form members in accordance with the first orsecond aspect of the invention on a casting floor to define anenclosure;

fastening the form members to the floor using fasteners passed throughthe apertures; and

pouring concrete into the enclosure.

Preferably, the form members form a plurality of enclosures, with atleast one form member being common to two enclosures.

Preferably, the method further includes the steps of:

allowing the concrete to set to form a panel; and,

lifting the panel into a desired position.

Preferably, the method further includes the step of unfastening at leastone of the form members defining the enclosure from the floor andremoving those form members prior to the step of lifting the panel.

Preferably, the step of arranging further comprises placing exteriorform members in two parallel lines and placing form members extendingbetween the parallel lines to define enclosures.

Preferably, the step of arranging comprises placing form members in agrid pattern to define enclosures.

Preferably, the step of pouring concrete into the enclosure comprisespouring concrete up to the level of the upright walls.

To those skilled in the art to which the invention relates, many changesin construction and widely differing embodiments and applications of theinvention will suggest themselves without departing from the scope ofthe invention as defined in the appended claims. The disclosures and thedescriptions herein are purely illustrative and are not intended to bein any sense limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are now described, by way of example only,with reference to the drawings in which:

FIG. 1 shows a form member in accordance with the prior art;

FIG. 2 a is a cross-section of a form member in accordance with thepresent invention;

FIG. 2 b is a partial perspective view of the form member shown in FIG.2 a;

FIG. 2 c is a partial plan view of the form member shown in FIG. 2 a;

FIG. 3 a is a cross-section of an extension piece for a form member inaccordance with the present invention;

FIG. 3 b is a partial perspective view of the extension piece shown inFIG. 3 a;

FIG. 3 c is a cross-section of an alternative extension piece inaccordance with the present invention;

FIG. 4 a is a cross-section of a second type of form member inaccordance with the present invention;

FIG. 4 b is a partial perspective view of the form member shown in FIG.4 a;

FIG. 5 is a plan view of a first arrangement of form members inaccordance with the present invention used for forming concrete panels;

FIG. 6 is a plan view of a second arrangement of form members inaccordance with the present invention used for forming concrete panels;

FIG. 7 is a front view of an end cap member in accordance with thepresent invention; and,

FIG. 7 b is a side view of the end cap member shown in FIG. 7 a.

DETAILED DESCRIPTION

FIG. 2 a is a cross-section of a form member 24 in accordance with thepresent invention. The form member comprises a pair of upright walls 10,11 which are connected at their inner surfaces 14, 15 by a plurality ofribs 16, 17 and a base member 18. The form member includes a pair ofchamfered surfaces 19, 20 extending between the upright walls 10, 11 andthe base member 18. In this example, the external surfaces of theupright walls 12, 13 are parallel to one another and substantiallyperpendicular to the base member. However, it should be appreciated thatthe external surfaces can have any desired profile. It should also beappreciated that the chamfered surfaces 19, 20 are optional as is basemember 18. The form member 24 also includes a flat top surface 25. Thisflat top surface is also optional.

The form member is of substantially uniform cross-section, except for aseries of apertures for receiving fasteners positioned along its length.This is clearly seen in FIG. 2 b and in FIG. 2 c. FIG. 2 b is aperspective view of the form member shown in FIG. 2 a, but of only aportion of its length. FIG. 2 c is a plan view of a portion of the formmember shown in FIG. 2 a. The apertures are formed at correspondingpositions in each of the ribs, the base member and the top surface. Alarger aperture is formed in the top surface than in the uppermost rib16 for reasons that are explained below.

In this example, the form member is 6.5 metres in length and is 120 mmin height. However, form members in accordance with the invention may beof any desired length and height. The form member can be formed of anyrigid material, but in this example an aluminium alloy is used. Thealuminium alloy can be extruded to produce the desired form. The formmember is preferably painted with a suitable paint to prevent concretefrom sticking to it.

In use, the form member is fastened to a casting floor using a bolt 21.The bolt is inserted into the form member from the top (the opposite endto the base member) with the shaft of the bolt passing through aperturesin the top surface 25, the ribs 16, 17 and the base member 18. The head22 of the bolt rests on a seat provided by one of the rib members. Inthe example shown in FIG. 2 a, a washer is interposed between the bolthead and the rib member 16. The aperture on the top surface is largerthan the aperture formed in the rib member on which the bolt head reststo allow the bolt head to pass below the level of the top surface 25. Ahole is drilled into the floor to receive the bolt. The drill bit may belocated using the apertures of the form member to ensure a correctposition and angle. A plurality of bolts may be used, along the lengthof the form member to fasten it to the floor. Typically, 3 bolts per 6.5metre section are sufficient. This is considerably fewer fasteners thanare required in prior systems. Furthermore, bolts can be used on greenerconcrete than the self-tapping screws of the prior art, reducingconstruction time. The apertures in the rib members may be elongate toaccommodate a plurality of bolts or a series of discrete apertures maybe formed in the ribs as shown in FIG. 2 b. A plastic cap 23 can beplaced over the top of the bolt head 22 to protect it from wet concreteduring the screeding process, as will be explained below. Each bolt mayhave an individual cap or a single cap may be shaped to cover aplurality of bolt heads.

The bolt head is positioned close to the top of the upright walls butcrucially does not extend above them. The bolt head can be covered witha cap which similarly does not extend above the upright walls when inuse. This is shown in FIG. 2 a and ensures that nothing extends abovethe level of the concrete during the screeding process. It is desirableto have the bolt head close to the top of the upright walls to allow forsimple installation and removal of the bolt. The cap is preferablyformed from a plastics material. The cap covers the bolt head and restson the same rib as the bolt head in this example. The cap fits into theaperture in the top surface snugly and is flush with the top surface.The cap prevents concrete from setting around the bolt head, which wouldmake removal of the bolt head difficult.

FIG. 3 shows a cross-section of an extension piece, which can be mountedon top of the form member shown in FIG. 2 to provide the form memberwith additional height. The extension piece comprises a pair of uprightwalls 30, 31 connected by ribs 32, 33. The ribs include apertures forreceiving a bolt shaft. The lower rib 33 provides a seat for a bolt headto rest against. In use, the extension piece 30 is placed on the formmember with the extension piece walls 31 lining up with form memberwalls 10, 11. A bolt is passed through the extension piece and the formmember into the floor. In this way, the external walls of the formmember are effectively increased in height allowing for the formation ofthicker concrete panels. In this example the extension piece adds 30 mmallowing for panels 150 mm thick to be formed. It should be appreciatedthat the walls 31 of the extension piece can have any desired exteriorprofile. For example, as shown in FIG. 3 c, the extension piece couldhave chamfered surfaces 35 that mirror chamfered surfaces 19, 20. It isalso possible to use a plurality of extension pieces, stacked on top ofone another. The plastic cap is fitted to the extension piece instead ofto the underlying form member in the same manner as it is to the formmember 24 when an extension piece is not used. If necessary a differentheight plastic cap can be used for the extension piece.

FIG. 4 is a cross-section of a second type of form member 40 inaccordance with the present invention. In use, form member 40 is used asan exterior element in a concrete panel forming arrangement and so willbe referred to as an exterior form member throughout the specification.Exterior form member 40 is a two piece aluminium alloy extrusion.However, any rigid material may be used and the form member may beformed using any suitable process. In this example, the two pieces ofthe exterior form member 40 are welded together. The two pieces areformed with an interlocking section 48, which ensures that they areproperly aligned and firmly joined. Form member 40 comprises a long wall41 and a short wall 42. The long wall and the short wall meet at acorner and extend substantially perpendicular to one another. Theexterior form member is strengthened by a back wall 43 connected to thelong wall and the short wall by ribs or solid portions 44. The back wall43 includes a portion substantially parallel to the long wall 41, aportion substantially parallel to the short wall 42 and an angledportion connecting the two. The exterior form member has substantiallyuniform cross-section and extends as shown in FIG. 4 b. In this example,the long wall is 150 mm long, the short wall is 120 mm long and the formmember extends 6 metres. FIG. 4 b is a perspective view of one end ofthe exterior form member 40. However, the form member 40 may be of anydesired dimensions.

In use the exterior form member 40 may be in one of two orientations.Depending on the thickness of the concrete panels that are to be formed,the long wall may either form an upright wall in contact with the pouredconcrete or may form a base member in contact with the casting floor. Ifit is desired to form panels of 150 mm thickness then the long wall 41is in an upright position and the short wall is in contact with thefloor. The exterior form member is fastened to the casting floor usingbolts at intervals along its length, typically a couple of metres apart.Bolt holes 45 are drilled through the exterior form members in the longwall 41 and bolt holes 46 are drilled through short wall 42. Theexterior form member is preferably solid in the regions around the boltholes 45, 46 to provide sufficient strength and rigidity. In a fastenedposition, the bolt heads rest against the back wall 43.

Exterior form member 40 does not include a chamfered surface which inuse is in contact with the poured concrete as it is not necessary ordesirable to have chamfers on the top or bottom edges of the concretepanels. The use of specific exterior form members as described meansthat when laid out the form members can abut each other without any gapsthough which concrete could escape. It also means that extension piecesare not necessary for the exterior form members as they can be arrangedfor two different thicknesses of panel. The exterior form members canalso be designed to be strong enough to resist the pressure exerted bythe poured concrete from one side.

FIG. 5 shows a plan view of a plurality of form members in accordancewith the present invention, laid out on a casting floor to define mouldsfor concrete panels. The form members are laid out to define a series ofadjacent enclosures 50 into which wet concrete is poured. In thisexample, exterior form members 40 form opposite sides of the enclosures.Form members 24 are placed between the exterior form members atsubstantially right angles to the exterior form members to formrectangular enclosures. Extension pieces are placed on form members 24if necessary to align with the top of exterior form members 40. Thearrangement is such that a number of form members 24 are common to twoenclosures. This arrangement of common form members has the advantagethat adjacent panels will always fit together in the lifted position,regardless of whether the sides are not accurately square with the basedue to errors made during the laying of the forms. This reduces theamount of sealant needed between the panels.

It should be appreciated that form members in accordance with thepresent invention can be used to form individual concrete panels butthat there are clear advantages in space, material and labour to forminga plurality of panels together, with form members which are common tomore than one panel.

A method of forming concrete using form members of the type shown inFIGS. 2-4 will now be described. Firstly, the exterior form members arelaid out on the casting floor parallel to one another. If more than oneform exterior member is required on each side, lugs connecting adjacentexterior form members 40 can be placed in conduit 47 formed between thefront wall 42 and the back wall 43 of the exterior form members. Thelugs will ensure that the form members are correctly aligned. Theinterior form members 24 are then positioned extending between theexterior form members 40 to define enclosures, as shown in FIG. 5. Theform members are fastened to the floor using bolts and plastic capsplaced over the bolt heads of the interior form members 24. Adhesivetape is used to cover unused bolt holes 45, 46 in the exterior formmembers. Concrete is then poured into the enclosures defined by the formmembers up to the level of the top of the form members. The top surfaceof the concrete is smoothed over and any excess concrete can be pushedinto the adjacent enclosure before filling and smoothing the adjacentenclosure. This reduces wastage of concrete.

The concrete is then left to cure. During curing the concrete is screedusing a power float machine which passes across the top surface of theenclosures. By placing the panels side by side with common form members,the power float can pass directly from one panel to the next without theneed for lifting the machine off and on different panels. Furthermore,the panels can be poured consecutively and then screed consecutively. Inprior systems in which each panel had separate form members, the powerfloat had to be continuously moved from one panel to the next to keep upwith the different stages of curing that the panels had reached.

Once the concrete is set, the form members from one side of the panelare unfastened and removed the crane used for tilting the panel thenapproaches the panel from the side from which the forms have beenremoved and tilts the panel up into position. The remaining forms fromthat panel are then removed and the crane moves forward to lift the nextpanel in the same manner. This method provides for quick and efficientlifting and positioning of the panels, reducing the time required forcrane usage, another significant expense in tilt-up construction. Onceall the panels have been lifted into position the remaining form membersare removed and the floor cleaned.

FIG. 6 shows a plan view of an alternative layout of form members inaccordance with the present invention. FIG. 6 shows a plurality of formmembers of the type shown in FIGS. 2 a-2 c laid out in a grid. There areno exterior form members used, although they could replace the outermostform members.

The form members are laid out to form a grid of enclosures, with formmembers abutting each other at right angles. Owing to the chamferedsurfaces 19, 20, a gap is present between two form members abutting atright angles. This gap can be plugged with an appropriately shaped pieceof ply wood or using a custom made plug formed from aluminium alloy,plastic or any other suitable material.

In order to prevent a form member 24 from becoming clogged withconcrete, concrete dust and dirt the cavities between the upright wallsat the ends of the form member 24 can be filled with expanding foamprior to use. Extension pieces can be sealed in the same way.

As an alternative, FIG. 7 shows an end cap 70 that can be used to sealthe end of a form member 24 to prevent it becoming filled with concreteand concrete dust. FIG. 7 a is a front view of the end cap, which hasthe same shape as the end of a form member 24. Raised portions 71 areshaped to fit in the cavities defined by the form member 24 to retainthe end cap in place. FIG. 7 b shows the end cap from the side. The endcap of FIG. 7 is preferably formed from a plastics material but may beformed from any suitable material.

The end cap may be shaped to fill the gap between two form members 24abutting each other at right angles in a grid, as described above.

End cap members may also be provided to fit the ends of the extensionpieces shown in FIG. 3.

The system of the present invention has a number of advantages over theprior art. The forms are strong, robust and easily and quickly cleanedfor reuse as compared with prior plywood forms. They will not be damagedduring removal or screeding and retain substantially the same dimensionsregardless of the conditions, e.g. they do not expand by absorbingmoisture and they will not be affected by sunlight. The forms can bemade of uniform height and extension pieces can be used to adjust theirheight. The forms are easily fastened to and unfastened from the flooras the bolt heads are easily accessed. Separate chamfer strips are notrequired as the forms can be made to include any desired exteriorprofile in a one piece extrusion or moulding.

The method of the present invention also has a number of inherentadvantages. The forms can be used for two panels simultaneously, savingtime and labour and allowing more panels to be formed per square metreof floor. The forms can be laid out in a grid to provide for optimal useof space and labour. The screeding process is made simple as the powerfloat can move across all the panels freely without the need for liftingthe power float on and off. There is less overflow of concrete on to thecasting floor; this reduces the clean up time required and saves cost.The time required for cranage is also reduced as the crane can moveswiftly from one panel to the next.

It is to be understood that the scope of the invention is not limited tothe described embodiments and therefore that numerous variations andmodifications may be made to these embodiments without departing fromthe scope of the invention as set out in this specification. Forexample, whilst the use of exterior form members has been described, itis possible to form enclosures for forming concrete panels using onlyform members of the type shown in FIG. 2.

1. An apparatus for use in forming a concrete panel comprising a rigidform member, the form member comprising: a pair of upright walls, havinginternal surfaces facing one another and external surfaces facing awayfrom one another; and a plurality of ribs connecting the internalsurfaces of the walls, wherein the ribs each include an aperture toallow a fastener shaft therethrough.
 2. The apparatus according to claim1, wherein the form member further includes a base portion including atleast one chamfered surface extending outwardly from the exteriorsurface of one of the walls.
 3. The apparatus according to claim 2,wherein the base portion includes two chamfered surfaces, one extendingoutwardly from each of the exterior surfaces of the walls.
 4. Theapparatus according to claim 2, wherein each chamfered surface issubstantially non-perpendicular to the ribs.
 5. The apparatus accordingto claim 1, wherein the form member is formed in one piece.
 6. Theapparatus according claim 1, further comprising a bolt having a shaftand a head, wherein, in use, the bolt shaft passes through the aperturesand into a floor on which the form member sits.
 7. The apparatusaccording to claim 6, wherein the rib furthest from the floor provides aseat on which the bolt head rests.
 8. The apparatus according to claim6, wherein in use, the upright walls extend above the extent of the bolthead.
 9. The apparatus according to claim 6, further including a cap,adapted to cover the bolt head.
 10. The apparatus according to claim 9,wherein in use, the cap does not extend above the upright walls.
 11. Theapparatus according to claim 9, wherein the cap rests on the ribfurthest from the floor.
 12. The apparatus according to claim 1, furtherincluding an extension piece, adapted to fit on the rigid form member atthe opposite end to a base portion, the extension member comprising apair of walls connected by a plurality of rib members.
 13. The apparatusaccording to claim 12, wherein the rib members of the extension pieceeach include an aperture to allow a fastener shaft therethrough.
 14. Theapparatus according to claim 1, wherein the form member is formed froman aluminium alloy.
 15. The apparatus according to claim 12, wherein theextension piece is formed from an aluminium alloy.
 16. The apparatusaccording to claim 1, wherein an end of the form member is sealedbetween the upright walls.
 17. The apparatus according to claim 1,further comprising an end cap, wherein the end cap covers an end of theform member to prevent concrete entering a space between the uprightwalls.
 18. A kit for forming concrete panels comprising a plurality ofform members in accordance with any one of the preceding claims and aplurality of exterior form members, wherein each exterior form membercomprises a first wall, and a second wall, wherein the second wall issubstantially perpendicular to the first wall and connected to the firstwall to form a corner, wherein the second wall is substantially shorterthan the first wall and wherein each of the first and second wallsinclude apertures therethrough.
 19. The kit according to claim 18,wherein the exterior form members are formed from aluminium alloy. 20.The kit according to claim 18, wherein the exterior form members areeach formed in two parts.
 21. A method of forming a concrete panel,comprising the steps of: arranging a plurality of form members or a kitof form members in accordance with any one of the preceding claims on acasting floor to define an enclosure; fastening the form members to thefloor using fasteners passed through the apertures; and pouring concreteinto the enclosure.
 22. The method according to claim 21, wherein theform members form a plurality of enclosures, with at least one formmember being common to two enclosures.
 23. The method according to claim21, further including the steps of: allowing the concrete to set to forma panel; and lifting the panel into a desired position.
 24. The methodaccording to claim 23, further including the step of unfastening atleast one of the form members defining the enclosure from the floor andremoving those form members prior to the step of lifting the panel. 25.The method according to claim 21, wherein the step of arranging furthercomprises placing exterior form members in two parallel lines andplacing form members extending between the parallel lines to defineenclosures.
 26. The method according to claim 21, wherein the step ofarranging comprises placing form members in a grid pattern to defineenclosures.
 27. The method according to claim 21, wherein the step ofpouring concrete into the enclosure comprises pouring concrete up to thelevel of the upright walls.